Process for the manufacture of chlorosulphonic acid



Patented Feb. 21, 1933 UNITED STATES PATENT ,GFFHCE ED'UAB-IDKRUMMENACHER, 0F RIEEEN, NEAR BASEL, SWITZERLAND, ASSIGNOR TO THE FIRMOF SOCIETY OF CHEMICAL TNDUSTBY IN BASLE, 0F BASEL, SWITZER- LANDPROCESS FOR THE MANUFACTURE OF CHLOROSULPHONIC ACID No Drawing.Application filed August 1, 1932, Serial No. 627,224, and in Switzerlandand Germany August 17, 1931.

It has been found that chlorosulphonic acid can be made in a very simplemanner by causing to act on a solution of approximately 2 moles SO inapproximately 1 mole H 80 approximately 1 equivalent weight of a metalchloride, or by caus ing to act on a solution of approximately 3 molesS0 in approximately 1 mole H SO, approximately 2 equivalent weights of ametal chloride, and separating the formed chlorosulphonic acid from thereaction mixture.

Particularly good results with regard to making the most of thecomponents used for this reaction, as Well as with regard to the yieldand purity of the produced chlorosulphonic acid are obtained if asolution of 2 moles S0 in 1 mole H 80 and l equivalent weight of a metalchloride, or a solution of 3 moles S0 in 1 mole H SO and 2 equivalentweights of a metal chloride are used.

The most various metal chlorides come into consideration for carryingout the present invention, such as, for example, the alkali chlorides,such as sodium chloride and potassium chloride, further magnesiumchloride, ferric chloride, barium chloride, calcium chloride oraluminium chloride. Particuluarly advantageous is the use of the cheapsodium chloride.

The conversion, which in the present invention is for example effectedby employing sodium chloride, proceeds mainly in accordance with thefollowing equations such as, for example, by suction or by distillation.

The following examples illustrate the invention the parts being byweight 2- Ewample J 120 parts of dry, finely ground sodium chloride areintroduced cautiously, whilst stirring, into 340 parts or" oleum havinga content of S0 of 70 per cent in a reflux apparatus, care being takenthat neither hydrogen chloride nor sulphur trioxide escapes from thereflux condenser. During the introduction of the sodium chloride thetemperature rises to about 150 C. (boiling point of chlorosulphonicacid) owing to the heat liberated by the reaction. This temperature ismaintained for some time after the salt has been introduced and thechlorosulphonic acid is finally distilled from the pasty mass which hasformed.

Ewample 2 60 parts of dry, finely ground sodium chloride are introducedcautiously whilststirring, into 260 parts of oleum having a content ofS0 of 62 per cent in a reflux apparatus, care being taken that neitherhydrogen chloride nor sulphur trioxide escapes from the refluxcondenser. After the salt has been introduced, the reaction mass ismaintained for sometime at a temperature of about 150 C. and thechlorosulphonic acid is then separated from it by distillation.

What I claim is 1. Process for the manufacture of chlorosulphonic acid,consisting in causing to act on a solution of approximately 2 moles S0in approximately 1 mole H SO, approximately 1 equivalent weight of ametal chloride. or by causing to act on a solution of approximately 3mol s S0 in approximately 1 mole H SO approximately 2 equivalent weightsof a metal chloride, and separating the formed chlorosulphonic acid fromthe reaction mixture.

2. Process for the manufacture of chlorosulphonic acid, consisting incausing to act on a solution of 2 moles SO in 1 mole H SO 1 equivalentweight of a metal chloride, or by causing to act on a solution of 3moles S0 in 1 mole H SO 2 equivalent weights of a metal chloride, and searating the formed chlorosulphonic acid rom the reaction mixture.

3. Process for the manufacture of chlorosulphonic acid, consisting incausing to act on a solution of 3 moles S0 in 1 mole H,SO 2 equivalentweights of a metal chloride, and separating the formed chlorosulphonicacid from the reaction mixture.

4. Process for the manufacture of chlorosulphonic acid, consisting incausing to act on a solution of 3 moles SO in 1 mole H SO 2 equivalentweights of an alkali chloride, and se arating the formed chlorosulphonicacid mm the reaction mixture.

5. Process for the manufacture of chlorosulphonic acid, consisting incausing to act on a solution of 3 moles S0 in 1 mole H50. 2 equivalentweights of an alkali chloride, and se arating the formed chlorosulphonicacid mm the reaction mixture by distillation.

6. Process for the manufacture of chlorosulphonic acid, consisting incausing to act on a solution of 3 moles SO in 1 mole H 80 2 equivalentweights of sodium chloride, and separating the formed chlorosulphonicacid from the reaction mixture by distillation.

In witness whereof I have hereunto signed my name this 20th day of July,1932.

EDUARD KRUMMENACHER.

